Growing perennials from seed

From Gardening Wiki

It will be well to sow the new crop of perennials seed on the first of August or thereabouts. Bloom cannot be looked for in some cases the next year, unless the seedlings are given the benefit of a hot-bed later, but the plants will have a better start than if the seed is held over the winter.

Sow in a coldframe or in the open in a seed-bed, which it is always well to have on the place for this purpose and for cuttings of perennials. Proceed as with the May sowing of seed, but shade with laths and be careful that the ground does not dry out. Transplant the seedlings in rows when large enough. They may then be removed to permanent positions in autumn or wintered where they are.